Risk assessment of perflurinated alkyl acids in food and drinking water

Perfluoroalkyl acids (PFAAs) and related compounds are anthropogenic compounds produced because of their temperature resistance and surface activity properties. Perfluooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) exposure is decreasing in Sweden. Temporal trends of perfluorohexane sulfonate (PFHxS) temporal trends vary within the country, due to differences in local contamination of drinking water. There is a good margin between the general population´s intake of PFOS and PFOA and the tolerable intakes determined by Efsa in 2008. Certain areas in Sweden are polluted by PFOS and PFHxS due to extensive use of firefighting foams. In these areas PFOS levels in edible fish can reach up to several hundred ng/g fresh weight. Regular consumption of highly contaminated fish a few times per week among children results in small or no margins to EFSA´s tolerable intake of PFOS. In some polluted areas groundwater is also PFOS and PFHxS contaminated. However, there is still a margin between high intakes from drinking water and the tolerable intake of PFOS. No health-based tolerable intake has been established for PFHxS. A cumulative risk assessment of the PFAA mixture detected in Swedish food suggests that current background intake of PFAA is not a risk for liver and reproductive toxicity. However several uncertainties make it difficult to draw firm conclusions about health risks. The knowledge about PFAA levels in food and drinking water in Sweden is still limited. No nation-wide effort to survey the occurrence of PFAA-contaminated sites has been made. Basic toxicological knowledge is lacking for many PFAA. Recent animal studies suggest that PFOS and PFOA are more toxic than reported in the Efsa risk assessment from 2008. The scientific basis for the tolerable intakes of PFOS and PFOA should be updated, and it should be determined if tolerable intakes of certain other PFAA can be established.